Large-scale plasma jet generation device and method

Abstract

A large-scale plasma jet generation device and method includes a jet tube and a jet chamber, wherein the jet tube outlet is located within the jet chamber, the jet chamber having an exhaust structure and an ambient gas intake structure, the ambient gas intake structure being used to introduce ambient gas into the jet chamber, the working gas ejected from the jet tube forming a circular flow within the jet chamber that flows toward the jet tube outlet, and after the ambient gas flows into the jet chamber, it flows toward the jet tube outlet under the action of the circular flow, changing the gas composition and flow field distribution near the jet tube outlet, thereby forming a large-scale plasma jet. By providing a jet chamber and adding an ambient gas intake structure to the jet chamber, the present invention changes the gas composition near the jet tube outlet while forming a gas circular flow, forming a large-scale plasma jet, increasing the processing area when the plasma acts on the processed object, and reducing application costs.

Description

Technical Field

[0001] The present invention relates to the technical field of plasma jet generation, and in particular to a large-scale plasma jet generation device and method. Background Art

[0002] In recent years, atmospheric pressure plasma jets have become a key technology in low-temperature plasma applications. By placing a metal rod as a high-voltage electrode within a hollow glass tube, with either a metal ring or no metal ring (using the distal end as the ground electrode), and applying an AC or pulsed high voltage, an outward-growing room-temperature plasma jet can be generated using a noble gas as the working gas. This jet achieves the spatial separation between the discharge region and the plasma treatment region in dielectric barrier discharge (DBD) technology, directly delivering active materials to the surface of the treated object, making it suitable for objects of various sizes and shapes. Plasma jets offer advantages such as low temperature, pollution-free operation, high efficiency, and controllability, making them suitable for a variety of applications such as surface cleaning, activation, coating, etching, and functionalization. Although plasma jets have garnered widespread attention and achieved significant progress in both mechanism research and application advancement, the plasma tends to shrink after exiting the jet tube, making it difficult to achieve uniform treatment over large areas, limiting their practical industrial applications.

[0003] Domestic and foreign scholars have conducted relevant research on methods to increase the plasma treatment area. The current methods used to increase the plasma treatment area mainly include the following aspects:

[0004] (1) Optimize the discharge electrode structure. By changing the electrode shape, spacing, angle, number, etc., the distribution and direction of the plasma jet can be adjusted, thereby increasing the treatment area. For example, using multi-needle or multi-hole electrodes can generate multiple plasma jets, and using curved or tilted electrodes can generate fan-shaped or circular plasma jets.

[0005] (2) Adjusting discharge parameters. By changing the discharge voltage, frequency, duty cycle, pulse width, etc., the intensity and stability of the plasma jet can be affected, thereby affecting the treatment area. For example, using high-voltage or high-frequency discharge can enhance the momentum and penetration ability of the plasma jet, while using pulsed or modulated discharge can reduce the instability and attenuation of the plasma jet.

[0006] (3) Changing discharge parameters and gas composition. By adjusting discharge voltage, current, frequency, duty cycle, pulse width, and other parameters, as well as changing gas type, mixing ratio, flow rate, and other conditions, the temperature, density, active particle concentration, and other characteristics of the plasma jet can be affected, thereby changing its diffusion range and treatment effect. Generally speaking, increasing the discharge energy and gas flow rate, as well as using helium or its mixed gas, can increase the treatment area of the plasma jet.

[0007] (4) Combining with other technical means. By combining with other technical means such as plasma array, mechanical scanning, magnetic field control, etc., the plasma jet processing area can be further increased. For example, the plasma array can directly increase the processing area of the plasma jet, mechanical scanning can be used to scan and process large-area materials, and magnetic field control can be used to change the shape of the plasma jet to increase the processing area.

[0008] However, the current research still has the following deficiencies: (1) The generation of plasma jets requires special design, which is not universal, and the effect of increasing the plasma treatment area is limited; (2) The discharge parameters have a great influence on the chemical activity of the plasma, but the direct effect on the plasma jet treatment area is limited; (3) The plasma treatment area can be increased by increasing the flow rate of He helium, but this will greatly increase the application cost of the plasma jet; (4) The plasma array will also increase the consumption of working gas. The mechanical scanning method requires the addition of a three-dimensional mobile system, and the magnetic field control method is complex to design.

[0009] Currently there is no simple and reliable way to increase the treatment area of a single plasma jet. Summary of the Invention

[0010] In order to solve the problem in the prior art that there is no simple and reliable method to increase the processing area of a single plasma jet, the present invention proposes a large-scale plasma jet generating device and method.

[0011] The technical problem of the present invention is solved by the following technical solutions:

[0012] A large-scale plasma jet generating device is characterized in that it includes a jet tube and a jet chamber, the outlet of the jet tube is located in the jet chamber, the jet chamber has an exhaust structure and an ambient gas intake structure, the ambient gas intake structure is used to introduce ambient gas into the jet chamber, the working gas ejected from the jet tube forms a circular flow in the jet chamber that flows toward the outlet of the jet tube, and after the ambient gas flows into the jet chamber, it flows toward the outlet of the jet tube under the action of the circular flow, changing the gas composition and flow field distribution near the jet tube outlet, thereby forming a large-scale plasma jet.

[0013] In some embodiments, the morphology of the jet can be adjusted by changing any one or more of the following factors: the number, shape, form and position of the ambient gas inlet structure; the type, proportion and flow rate of the ambient gas.

[0014] In some embodiments, the morphology of the jet can be adjusted by changing any one or more of the following factors: the discharge electrode structure; the number, shape, form and position of the exhaust structure; the rising edge, falling edge, pulse width and frequency of the pulse voltage waveform output by the discharge power supply; the type, proportion and flow rate of the working gas.

[0015] In some embodiments, the ambient gas may be introduced into any position of the jet chamber by the ambient gas inlet structure.

[0016] In some embodiments, the ambient gas intake structure may be an intake hole or an intake pipe.

[0017] In some embodiments, the exhaust structure allows the interior of the jet chamber to communicate with the external atmospheric pressure.

[0018] In some embodiments, a gas buffer chamber is further included, which is arranged at the inlet of the jet tube or connected to the inlet of the jet tube through a gas channel, and the gas buffer chamber is provided with a rare gas inlet and a dopant gas inlet; alternatively, the gas buffer chamber is omitted, and a sufficiently long gas mixing pipe is provided to connect the inlet of the jet tube, and the rare gas and the dopant gas are evenly mixed in the gas mixing pipe and then enter the jet tube.

[0019] In some embodiments, the doping gas introduced into the gas buffer chamber is a single gas or a mixed gas whose gas molecules can be ionized by metastable atoms of the introduced rare gas.

[0020] In some embodiments, the volume percentage of the doping gas introduced into the gas buffer chamber is 0.1-99%; a pulse voltage waveform with a rising edge and / or a falling edge in the micro-nanosecond level is applied between the electrodes of the jet tube.

[0021] The present invention also proposes a large-scale plasma jet generation method, which uses the large-scale plasma jet generation device to generate a large-scale plasma jet.

[0022] The beneficial effects of the present invention compared with the prior art include:

[0023] The present invention starts from the basic mechanism of plasma jet generation. On the one hand, by arranging the outlet of the jet tube in a jet chamber with an exhaust structure, an approximately closed environment rather than an open jet environment is formed outside the outlet of the jet tube, so that the working gas ejected from the outlet of the jet tube forms a loop airflow flowing toward the outlet of the jet tube in the closed discharge environment of the jet chamber, thereby changing the working gas concentration distribution near the outlet of the jet tube, solving the problem of contraction of the traditional plasma jet, and generating a diffuse plasma jet; on this basis, the present invention further introduces a mechanism for regulating the composition of the ambient gas, by adding an ambient gas intake structure in the jet chamber, introducing ambient gas into the jet chamber, and the ambient gas flows into the jet chamber and then flows toward the outlet of the jet tube, forming a gas circulation while changing the gas composition near the outlet of the jet tube, forming a large-scale plasma jet, increasing the processing area when the plasma acts on the processed object, reducing the application cost, and maintaining the original traditional jet shape at the center position. The present invention starts with the basic mechanism of plasma jet generation, and directly controls the flow field through the above two aspects of design, adjusts the flow field facet, diffusion trend, and gas component ratio change of the gas outflow jet nozzle, thereby changing the morphology of the plasma jet and improving the processing area of a single plasma jet. This large-scale plasma jet generation method has the significant advantage of effectively improving the plasma processing area, which can greatly improve the processing area of a single plasma jet, and is of great significance to the future industrial application of plasma jets. Moreover, the present invention can also solve the shortcomings of other methods for increasing the plasma processing area (such as jet arrays), avoid using plasma jet arrays or reduce the number of jet tubes of plasma jet arrays, reduce rare gas loss, and reduce application costs. In short, the large-scale plasma jet generation device and method proposed by the present invention can effectively solve the problem that the radial area of existing plasma jets is small and inconvenient for industrial application, and can be applied to most application fields of traditional plasma jets, such as material surface modification, medical disinfection and sterilization, pollution treatment, etc.

[0024] Other beneficial effects of the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic diagram of a large-scale plasma jet generating device in an embodiment of the present invention;

[0026] Figure 2 is a schematic diagram of a plasma jet in the prior art;

[0027] Figure 3 Schematic diagram of a plasma jet in an embodiment of the present invention;

[0028] The reference numerals are as follows:

[0029] 1-jet tube, 11-ground electrode, 12-high voltage electrode, 2-jet chamber, 3-gas buffer chamber, 4-air inlet, 5-exhaust port. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the accompanying drawings and in combination with preferred embodiments. It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0031] It should be noted that the directional terms such as left, right, up, down, top, and bottom in this embodiment are merely relative concepts, or are based on the normal use status of the product, and should not be considered as restrictive.

[0032] The morphology of plasma jets is closely related to the propagation of ionization waves, which in turn are affected by the gas composition and charge density distribution. Traditional plasma jets are generated in an open atmospheric environment. After the gas is ejected from the jet tube, the radial component is very small and there is a radial boundary where the gas composition changes sharply. It is also difficult to effectively adjust the ejected gas flow field. The existing methods for enhancing plasma jets are to increase the discharge voltage and optimize the jet tube structure, such as Figure 2 As shown, it only changes the length, intensity and shape of the plasma jet in the axial direction, which cannot effectively increase the radial area of the plasma jet.

[0033] Prior to the present invention, solutions to the technical problem of the plasma jet's small radial area included increasing the applied voltage, increasing the jet gas velocity, increasing the jet tube diameter, and employing a jet tube array. However, these methods failed to fundamentally address the problem because they did not alter the plasma jet's formation mechanism and instead presented numerous other drawbacks, as detailed below:

[0034] (1) Increasing the applied voltage of the plasma jet can enhance the formation effect of the plasma jet. However, since it is still a traditional form of plasma jet, the enhancement is more in the axial direction, and the radial plasma jet effect is limited. In addition, increasing the voltage will lead to an increase in discharge power, thereby increasing power loss and reducing efficiency.

[0035] (2) Increasing the jet gas velocity within a certain range can enhance the plasma jet effect. However, similar to (1), this only enhances the axial plasma jet effect, with limited radial enhancement. In addition, increasing the jet gas velocity increases the rare gas consumption rate, thereby greatly increasing the application cost of the plasma jet.

[0036] (3) Increasing the diameter of the jet tube to increase the plasma jet effect requires a higher applied voltage and a larger gas consumption, which will bring about the shortcomings of the first two methods (1) and (2).

[0037] (4) Increasing the plasma jet processing area by using a jet array will also increase the loss rate of rare gas and increase the application cost of the plasma jet. In addition, it is also necessary to solve the problems of discharge coupling and repulsion between the jet array units of the plasma jet.

[0038] In order to solve the problem that the existing plasma jet has a small radial area and is inconvenient for industrial application, the present invention proposes a large-area plasma jet generation device and method using ambient gas modulation in a closed space; the embodiment of the device is as follows Figure 1 As shown, it includes a jet tube 1 and a jet chamber 2. The outlet of the jet tube 1 is located in the jet chamber 2. The jet chamber 2 has an exhaust structure and an ambient gas intake structure. The ambient gas intake structure is used to introduce ambient gas into the jet chamber 2. The working gas ejected from the jet tube 1 forms a circular flow in the jet chamber 2 that flows toward the outlet of the jet tube 1. After the ambient gas flows into the jet chamber 2, it flows toward the outlet of the jet tube 1 under the action of the circular flow, changing the gas composition and flow field distribution near the outlet of the jet tube 1, thereby forming a large-scale plasma jet.

[0039] The present invention utilizes the introduction of additional ambient gas into the enclosed space of the jet chamber to alter the gas flow field distribution, working gas diffusion trend, and gas component ratio within the enclosed space, thereby increasing the radial propagation component of the ionization wave. This effectively increases the radial area of the plasma jet without increasing working gas loss. This device and method can significantly increase the radial processing area of a single plasma jet, which is of great significance for the future industrial application of plasma jets.

[0040] In addition, the present invention can also solve the shortcomings of the existing method of increasing the plasma processing area (such as the use of jet arrays in the existing technology), and can avoid the use of plasma jet arrays or reduce the number of jet tubes in the plasma jet array, thereby reducing the loss of rare gas and reducing the application cost of plasma jets.

[0041] Compared with existing technologies, the present invention offers the distinct advantage of achieving a single-tube, large-area plasma jet through flow field modulation without increasing the applied electrode voltage, gas flow rate, jet tube diameter, or the use of a jet tube array. This avoids the limitations of other previously mentioned approaches, facilitates the industrial application of plasma jets, and can be implemented with any conventional electrode structure capable of generating plasma jets.

[0042] like Figure 1As shown, in a specific embodiment, the large-scale plasma jet generating device includes two parts: a jet chamber 2 and a gas buffer chamber 3, which are connected through a jet tube 1. The gas buffer chamber 3 is located at the inlet of the jet tube 1, or the gas buffer chamber 3 is connected to the inlet of the jet tube 1 through a gas channel. The gas buffer chamber 3 is provided with two gas inlets 4, which are a rare gas inlet and a dopant gas inlet. The rare gas introduced into the gas buffer chamber 3 is helium, and the dopant gas introduced into the gas buffer chamber 3 can be air, nitrogen, oxygen, or any other rare gas except helium, which is ionized by metastable helium atoms. There is no restriction on the type and proportion of the gas; the mixed gas of the rare gas and the dopant gas is the working gas. The gas buffer chamber 3 is used to provide a buffer space for the working gas so that the rare gas and the dopant gas are fully mixed. In addition, the gas buffer chamber can also be connected to the inlet of the jet tube 1 through a gas channel instead of being directly set at the inlet of the jet tube 1. Alternatively, the gas buffer chamber can be omitted and a sufficiently long gas mixing pipe can be set to connect the inlet of the jet tube. The rare gas and the doping gas are evenly mixed in the gas mixing pipe and then enter the jet tube 1.

[0043] The outlet of the jet tube 1 is located within the nearly closed jet chamber 2. A circular exhaust port 5 is provided on the side wall of the jet chamber 2 facing the jet tube 1. The center of the annular exhaust port 5 is located on the axis of the jet tube 1. The exhaust port 5 connects the interior of the jet chamber 2 to the external atmospheric pressure, allowing gas to be exhausted while maintaining the gas pressure within the jet chamber 2 at atmospheric pressure.

[0044] An ambient gas inlet 4 is provided on the side wall of the jet chamber 2 at the rear side of the jet tube 1. The ambient gas inlet 4 can be in the form of an air inlet hole or an air inlet pipe, and is used to adjust the ambient gas composition in the jet chamber 2, thereby adjusting the generation morphology of the plasma jet. Figure 1 As shown, the dotted line at the outlet of the ambient gas inlet 4 is the flow field distribution of the ambient gas.

[0045] The volume percentage of the doping gas introduced into the gas buffer chamber 3 is 0.1 to 99%, and the ambient gas flow rate is less than or equal to the working gas flow rate. There is no restriction on the ambient gas introduction rate. Any change in the flow field at the jet tube outlet caused by increasing or decreasing the ambient gas flow rate is caused by applying a micron-nanosecond pulse voltage (or other pulse voltage waveforms with rising edges, falling edges, pulse widths, frequencies, etc. at the micron-nanosecond level) between the ground electrode 11 and the high-voltage electrode 12 of the jet tube. When the breakdown voltage is reached, a large-area plasma jet can be formed at the outlet of the jet tube 1, such as Figure 1 As shown, the dotted line at the outlet of the jet tube 1 is the flow field distribution of the working gas.

[0046] The principle of large-area plasma jet generation is as follows:

[0047] When the working gas is ejected from the jet tube 1 to the jet chamber 2, the jet chamber 2 is a nearly closed environment, and the ejected working gas will form a gas loop in the closed space. Figure 1 As shown by the dotted line at the outlet of the jet tube 1. In addition to axial propagation, the working gas ejected from the jet tube 1 also has a radial propagation component, generating a diffuse plasma jet. At the same time, the ambient gas inlet 4 introduces ambient gas into the jet chamber 2. Since the flow velocity is relatively high and the pressure is relatively low at the outlet of the jet tube 1, the ambient gas flows into the jet chamber 2 and then flows toward the outlet of the jet tube. Near the outlet of the jet tube 1, since the ejected working gas is affected by the dilution of the ambient gas, there is a radial trend of decreasing helium component, and there is no dividing line of sharp change. The gas components in the closed space are simultaneously affected by the combined influence of the working gas ejected from the jet tube and the ambient gas. While forming a diffuse plasma jet, the original traditional jet morphology can be maintained at the center position, thereby realizing the adjustment of the generation morphology of the plasma jet and providing conditions for large-area plasma generation.

[0048] In addition, the exhaust port 5 can be used to discharge excess gas in the discharge chamber, so that the helium component in the ambient gas inside the jet chamber is always smaller than the working gas, maintaining a dynamic balance.

[0049] The embodiment of the present invention also proposes a large-scale plasma jet generation method, which can achieve large-area uniform treatment without increasing the working gas consumption cost and power supply power, and has important value in future large-scale industrial applications.

[0050] The embodiment of the present invention starts from the basic mechanism of plasma jet generation, and adjusts the flow field distribution, diffusion trend, and gas component ratio change at the outlet of the gas jet tube by directly controlling the flow field, thereby changing the radial morphology of the plasma jet. Based on the use of the closed space of the jet chamber to generate a diffuse plasma jet, the embodiment of the present invention introduces a mechanism for regulating the composition of the ambient gas. The large-scale plasma jet generated is as follows: Figure 3 As shown, while forming a diffuse plasma jet, the original traditional jet shape can be maintained at the center position. This large-scale plasma jet generation method has the effect of effectively increasing the plasma processing area.

[0051] In various embodiments, the flow field distribution and morphology of the plasma jet can be adjusted by changing any one or more of the following factors: the number, shape, form, and location of the air inlets for introducing ambient gas into the jet chamber; the number of air inlets can be changed from 1 to N, with no upper limit; the air inlet structure can be in the form of an air inlet hole, and the shape of the air inlet hole can be changed from an annular shape to a circular, square, porous, or any other shape; the air inlet hole can be changed to any tubular air inlet tube extending into any position within the closed chamber, thereby allowing for more flexible adjustment of the gas flow field outside the jet tube outlet; the air inlet hole can also be moved from the jet chamber sidewall facing the jet tube to any position within the closed jet chamber, thereby directly changing the flow field distribution of the working gas after it flows out of the jet tube outlet. The type and flow rate of the introduced ambient gas are not limited, and any additional air inlet, in addition to the working gas, can be used to change the gas flow field and gas composition within the closed chamber, thereby adjusting the plasma jet morphology.

[0052] On the basis of ambient gas modulation, the morphology of the plasma jet can also be adjusted by parameters such as the rising edge, falling edge, pulse width, and frequency of the pulse voltage waveform output by the discharge power supply. The parameters of the discharge power supply are not limited, and the embodiments of the present invention do not impose any restrictions on this.

[0053] The method for generating a large-area passive plasma jet by regulating the flow field and components in a closed space by means of ambient gas proposed in an embodiment of the present invention does not impose any restrictions on the shape of the jet chamber and the gas buffer chamber, or the electrode structure of the jet tube. As long as the flow field and components in the closed space are changed by means of ambient gas, the changes in the plasma jet morphology are within the scope of the embodiment of the present invention.

[0054] Compared with the existing scheme, the present invention starts from the basic mechanism of plasma jet generation. On the one hand, by setting the outlet of the jet tube in a jet chamber with an exhaust structure, an approximately closed environment rather than an open jet environment is formed outside the outlet of the jet tube, so that the working gas ejected from the outlet of the jet tube forms a loop airflow flowing toward the outlet of the jet tube in the closed discharge environment of the jet chamber, thereby changing the working gas concentration distribution near the outlet of the jet tube, solving the problem of contraction of the traditional plasma jet, and generating a diffuse plasma jet; on this basis, the present invention further introduces a mechanism for regulating the composition of the ambient gas, by adding an ambient gas intake structure in the jet chamber, introducing ambient gas into the jet chamber, and the ambient gas flows into the jet chamber and then flows toward the outlet of the jet tube, forming a gas circulation while changing the gas composition near the outlet of the jet tube, forming a large-scale plasma jet, increasing the processing area when the plasma acts on the processed object, reducing the application cost, and maintaining the original traditional jet shape at the center position. The present invention starts with the basic mechanism of plasma jet generation, and directly controls the flow field through the above two aspects of design, adjusts the flow field facet, diffusion trend, and gas component ratio change of the gas outflow jet nozzle, thereby changing the morphology of the plasma jet and improving the single plasma processing area. This large-scale plasma jet generation method has the significant advantage of effectively improving the plasma processing area, which can greatly improve the processing area of a single plasma jet, and is of great significance to the future industrial application of plasma jets. Moreover, the present invention can also solve the shortcomings of other methods for increasing the plasma processing area (such as jet arrays), avoid the use of plasma jet arrays or reduce the number of jet tubes of plasma jet arrays, reduce rare gas loss, and reduce application costs. In short, the large-scale plasma jet generation device and method proposed by the present invention can effectively solve the problem that the radial area of existing plasma jets is small and inconvenient for industrial application, and can be applied to most application fields of traditional plasma jets, such as material surface modification, medical disinfection and sterilization, pollution treatment, etc.

[0055] The above description further details the present invention in conjunction with specific / preferred embodiments, and the specific implementation of the present invention should not be construed as being limited to these descriptions. Persons skilled in the art will appreciate that, without departing from the spirit of the present invention, they may make various substitutions or modifications to the described embodiments, and these substitutions or modifications should be considered to fall within the scope of protection of the present invention. Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "preferred embodiments," "examples," "specific examples," or "some examples" indicates that the specific features, structures, materials, or characteristics described in conjunction with such embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Persons skilled in the art may combine and assemble the different embodiments or examples described in this specification, as well as features of different embodiments or examples, without conflicting opinions. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications may be made herein without departing from the scope of protection of the patent application.

Claims

1. A large-scale plasma jet generating device, characterized in that: The invention comprises a jet tube and a jet chamber, wherein the outlet of the jet tube is located in the jet chamber, and the jet chamber has an exhaust structure and an ambient gas intake structure, wherein the ambient gas intake structure is used to introduce ambient gas into the jet chamber, and the working gas ejected from the jet tube forms a circular flow in the jet chamber that flows toward the outlet of the jet tube, and after the ambient gas flows into the jet chamber, it flows toward the outlet of the jet tube under the action of the circular flow, thereby changing the gas composition and flow field distribution near the outlet of the jet tube, thereby forming a large-scale plasma jet.

2. The large-scale plasma jet generating device according to claim 1, characterized in that: The morphology of the jet can be adjusted by changing any one or more of the following factors: the number, shape and position of the ambient gas inlet structure; the type, proportion and flow rate of the ambient gas.

3. The large-scale plasma jet generating device according to claim 1, characterized in that: The jet morphology can be adjusted by changing any one or more of the following factors: the discharge electrode structure; the number, shape and position of the exhaust structure; the rising edge, falling edge, pulse width and frequency of the discharge power supply output pulse voltage waveform; the type, proportion and flow rate of the working gas.

4. The large-scale plasma jet generating device according to claim 1, characterized in that: The ambient gas can be introduced into any position of the jet chamber by the ambient gas inlet structure.

5. The large-scale plasma jet generating device according to claim 1, characterized in that: The ambient gas intake structure may be an intake hole or an intake pipe.

6. The large-scale plasma jet generating device according to claim 1, characterized in that: The exhaust structure enables the interior of the jet chamber to communicate with the external atmospheric pressure.

7. The large-scale plasma jet generating device according to claim 1, characterized in that: It also includes a gas buffer chamber, which is arranged at the inlet of the jet tube or connected to the inlet of the jet tube through a gas channel, and the gas buffer chamber is provided with a rare gas inlet and a dopant gas inlet; alternatively, the gas buffer chamber is omitted, and a sufficiently long gas mixing pipe is provided to connect the inlet of the jet tube, and the rare gas and the dopant gas are evenly mixed in the gas mixing pipe and then enter the jet tube.

8. The large-scale plasma jet generating device according to claim 7, characterized in that: The doping gas introduced into the gas buffer chamber is a single gas or a mixed gas whose gas molecules can be ionized by metastable atoms of the introduced rare gas.

9. The large-scale plasma jet generating device according to claim 1, characterized in that: The volume percentage of the doping gas introduced into the gas buffer chamber is 0.1-99%; a pulse voltage waveform with a rising edge and / or a falling edge in the micro-nanosecond level is applied between the electrodes of the jet tube.

10. A method for generating a large-scale plasma jet, characterized in that: A large-scale plasma jet is generated using the large-scale plasma jet generating device according to any one of claims 1 to 9.

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